This invention pertains generally to mobile spray units for spraying liquid chemicals and the like and has particular relation to such a unit with an improved anti-drift shield to confine the spray to a designated target area.
In the application of chemicals in the agriculture industry it is common that the spray apparatus be positioned behind moving equipment, and as a result of this as well as the natural wind and air disturbances that occur, the accuracy of the spray application may be affected. This in turn may reduce the quality of the pest control that is obtained and also may contaminate non-target areas. In order to minimize these problems, it is known to use anti-drift shields with the spray equipment in order to more effectively restrict the spray application to a designated target area. While various shield configurations have been employed for particular uses, they are rather restricted in where they may be used in a satisfactory manner and are generally not adaptable to a wide variety of conditions such as very irregular topographies, vegetation height and spray nozzle patterns. Further, these various shield configurations tend not to accommodate full view of spray nozzle performance, while at the same time providing shroud protection from wind.
U.S. Pat. Nos. 3,977,605 and 4,186,879 each disclose mobile spray units utilizing a rigid spray housing or shield with there being provided at the lower end of the housing or shield a relatively small flexible shroud or baffle. In the '605 patent this flexible shroud, identified at 64, extends all the way around the shield, while in the '879 patent the flexible sections 54 and 60 are on the front and rear walls only.
U.S. Pat. No. 4,804,145 discloses a mobile compost spreader that utilizes a drape of flexible material that extends around the discharge side of the dispensing brush. Accordingly, this is a 3-sided drape against which the compost material impinges.